When laying a foundation for a wind turbine, a reinforced concrete element is often cast and subsequently, the turbine tower is positioned on the concrete element and fixed hereto. A simple way of fixing the tower to the concrete element is to anchor substantially vertical anchor rods in the concrete element, and attach these to a flange which is attached to the tower wall.
Due to the heavy weight of the tower construction, the anchor rods and the concrete element will be exposed to a large pressure at points carrying the tower. Even though the foundation is levelled before positioning the turbine tower, the anchor rods are exposed to a large pressure from the tower.
Traditionally, final levelling of the tower construction is carried out while a crane supports the tower. After levelling of the tower construction, an additional casting layer, sometimes referred to as grouting, is added to fill out a gap between the concrete element and the levelled flange. Additionally, the grouting may fix the levelled position. The crane is used to keep the tower construction in place while the additional casting layer hardens.
Due to the increasing size of wind turbines, the size of the supporting crane is also increasing which further increases the associated cost and time consumption.